So I am looking to put together a router and have heard that there are discussions comparing moving table vs moving gantry designs. From what I've gathered the gantry design is said to be easier to manufacture and less expensive. On the other side all that I've heard is that a moving table can be much more ridged but requires a much larger footprint. My biggest concern is the rigidity of a moving gantry design with a single lead screw and the possibility of rotation about the y axis. Wondering also where the the difficulty is greater to produce a moving table vs moving gantry. I can see using black gas pipe and skate bearings for both methods. Just hoping to have a discussion comparing the options as i couldn't find much of one up to this point.

I'd say the moving table is easier to build.

Driving a gantry with a single screw will almost always allow some skewing in the gantry. To avoid this you'll need a large box like structure tying the two sides together under the table, and the bearings on each side spread apart as far as possible.

That was my initial impression as well, within the faq there is a post very briefly stating that a gantry would be easier but I just don't see it. The cost increased due to the need for two drives to keep square as well. The only real drawback to a moving table is the fact you'll need double the length for the table axis.

The only real drawback to a moving table is the fact you'll need double the length for the table axis.

Another minus is that the load/inertia is going to change, depending on the varying material load which has to be carried by the moving table.
Al.

What are the big benefits to using a moving gantry design? It seems to be the common design being used right now.

try this....
http://www.cnczone.com/forums/showthread.php?t=51656

andy